Global food production is expected to increase substantially by 2050 to meet the increasing demands of the burgeoning population coupled with changing diets and the growing per capita consumption that is a function of rising incomes in many countries ( Ray et al., 2013; Tilman et al., 2011). Agriculture continues to be a pillar of the population, with around 54% of the population (especially, those in rural areas) relying on it for their livelihoods. Agriculture contributed 18.3% to Ghana’s Gross Domestic Product (GDP) in 2017 ( MoFA, 2017). Crop production, especially cassava, is an important economic activity in Ghana and the world at large. It serves as food for 800 million people in the world ( Fondong & Rey, 2018). Ghana is the third leading cassava producer in Africa and with a world share of 6.3%, it ranks sixth in terms of value and volumes. Per capita consumption per year in Africa is estimated at 80 kg and 152.9 kg for Ghana ( MoFA, 2009; Shipman, 2017 cited in Boateng, 2015). Cassava contributes 46% of the country’s agricultural GDP through trade ( Sen Nag, 2017). Cassava has a broad agro-ecological adaptation and an in-ground storage capability and capacity that allows for flexible harvesting to ensure all year-round food availability ( Sanginga & Mbabu, 2015; Torkpo et al., 2017). The commodity once described as “food for the poor” ( FAO, 2013) is consumed in all regions of Ghana ( Bayitse et al., 2017) and is now envisaged as a strategic crop that could transform the Ghanaian economy as it has great potential for industrialization due to its high starch content and varied product utilization ( Bayitse et al., 2017). In 2017, domestic production stood at 19,137.94 metric tons, which was a 7.5% increase over the previous year’s output. This resulted from a 5.3% change in cropped area due to the government program; Planting for Food and Jobs ( MoFA, 2017). In spite of its potential, cassava’s productivity in African smallholder’s farming systems is still below the optimal level ( Elegba et al., 2013), though several efforts have been made by projects and programs in disseminating improved cultivars and integrated pest and disease management practices ( Rusike et al., 2010; Zinga et al., 2013).

The gap in yield has been attributed to several factors, including plant diseases that result in food scarcity ( Zadoks, 2008). Cassava, with its long life cycle, is affected by numerous diseases and pests such as African cassava mosaic virus, cassava bacterial blight, anthracnose, root rot, green mite and whiteflies. The most devastating within the West African belt has been the Cassava mosaic virus ( Elegba et al., 2013; Manu-Aduening et al., 2007 and Moses et al., 2015). Cassava diseases are reported to cause losses of fresh roots as well as planting material. Reduction in root yields could differ considerably with the cassava cultivars’ vulnerability, changes in climate and the inoculum pressure ( Fondong & Rey, 2018; Kintché et al., 2017). Pest and disease spread have been on the increase due to cross-border trade, movement of people from one country to another and the sharing of planting materials amongst producers and countries resulting from regional integration ( Echodu et al., 2019).

With the high losses linked to pests and diseases, adoption of resistant cultivars and good management strategies in Ghana have not been encouraging, ostensibly because farmers have no or little access to cultivars and little knowledge of the pests and diseases as well as associated management practices. This is evidenced in studies that have investigated this issue in Ghana ( Acheampong et al., 2013; Cudjoe et al., 2005; Manu-Aduening et al., 2007; Torkpo et al., 2017). These few studies are often skewed towards examining farmers’ knowledge and or perception with little efforts to examine attitudes and practices; thereby not wholly applying the knowledge, attitudes and practices (KAP) model to better understand farmers’ behavior and actions. Therefore, this paper is intended to fill this gap. The KAP assessment reveals what people know about the issue being investigated, how they feel and their present actions. The framework assumes that a change in practices is the cumulative result of a change in knowledge and attitudes ( Schreinemachers et al., 2017). Despite the vital role of farmers’ knowledge in controlling and mitigating pests and diseases, the application of the KAP model is limited or non-existent in this discipline and our study intends to enrich the body of existing literature in this area. Efforts to improve the management of pests and diseases of cassava are likely to be hindered if farmers’ knowledge on crop pests and diseases and practices for handling them are not known and considered appropriately. Thus, understanding farmers’ knowledge, attitudes and practices related to crop pests and diseases and their management is central to crop protection through identifying farmers’ training needs and is necessary for the formulation and development of effective integrated management strategies. This study was specifically designed to:

The following two hypotheses were tested;

The purpose of the study was to examine and understand farmers’ knowledge, attitudes and practices in coping with cassava pests and diseases. Insights from this is central to crop protection and necessary for the development of effective integrated management strategies. The farmers’ characteristics revealed that most of the farmers have had some level of formal education and the study observed an improvement over other studies ( Asare-Bediako, 2014), which have reported low levels of education among farmers in rural areas. This observation may be due to the introduction of the Free and Compulsory Universal Education (FCUBE) policy introduced in Ghana in 1995 ( Akyeampong, 2009), which gave most of the people in rural Ghana, especially Northern Ghana, the opportunity to access education ( Ghana Statistical Service, 2013). The moderate level of education of farmers could expedite technology uptake and impact positively on any developmental program executed in the regions. The high number of farmers being household heads is a promising indicator as it could stimulate quick on-farm decision making in the area of investment and resource allocation, since the household heads control family resources. Membership of agriculture organizations presents an avenue to receive current information on agriculture and, more importantly, on pests and diseases, as well as support for advancing the farm as projects prefer working with organized groups.

According to Bloom’s taxonomy as cited in Kusumawardani et al. (2019), knowledge is the primary step of perception, which then generates attitudes and results in actions. With farmers representing a broad demographic pool with regard to experience, educational level, age, household head and household size, the study observed that the majority of the farmers had knowledge of the damaging pests specific to their crop. This finding is consistent with Echodu et al. (2019). The pests mentioned by farmers were among some of the common devastating cassava pests well documented in literature ( PlantVillage and Mathieu-Colas et al., 2009). Farmers’ over-reliance on their own experiences, intuition and farmer-to-farmer networks for knowledge of different pests could be problematic as the right information may be missed. Farmers were unaware of specific insect vectors with multiple species like whiteflies and mealybugs and classified them under one generic name, which could affect the appropriate management strategy being employed. Cudjoe et al. (2005) made a similar observation and reported that farmers were generally unaware of the Bemisia whiteflies and could not identify them by specific local names. Most of the pests mentioned by farmers are known to be insect vectors of viral, bacterial and fungal cassava diseases ( Fanou et al., 2017). For instance, whiteflies cause cassava mosaic disease and grasshoppers are known to carry the pathogen that causes cassava bacterial blight ( Fanou et al., 2017). Farmers’ knowledge on diseases was found to be limited, which is consistent with a study by Echodu et al. (2019) but contrasts that of Appiah-Kubi et al. (2015). Some farmers, though they noticed changes in the plant tissues, were unable to associate them with specific diseases. Disease descriptions depicted that pathogens attacked foliar tissues, stem and root tissues; thus, causing leaf spots, leaf dropping, wilting, die-back and rot. Pests, diseases and related symptoms were used interchangeably, demonstrating farmers’ knowledge gap in cassava diseases. These twists in responses revealed that farmers need intensive training on simple skills and tools in pest and disease identification and management. Our study has shown that mixed infections can occur on the farm, as reported by the farmers and confirmed by the disease symptoms statements. This adds to existing knowledge, since most studies on roots and tuber diseases in Africa ( Adam et al., 2015; Houngue et al., 2018; Torkpo et al., 2017 and Okonya et al., 2019) have only reported single infections, but in an open environment it is possible for multiple infections to occur. Questions on pests, diseases and symptoms did not plunge deeper to delineate the crop cycle stage attacked and the season of the cropping year in which these pests and diseases were prominent to affirm farmers’ responses. Further studies should incorporate these stages of the crop cycle and seasons as a means of validating farmers’ responses. Manu-Aduening et al. (2007) in their study on “Farmers’ perceptions and knowledge of cassava pests and diseases and their approach to germplasm selection for resistance in Ghana” realized inconsistencies in farmers’ responses and found cassava mosaic disease, anthracnose and brown leaf spot to be present on farmers’ fields. This indicates that these diseases have persisted for a long time, and efforts and investments should be geared towards its control to avoid them becoming epidemic.

Cassava, due to its long growth cycle, is exposed to varying pests, diseases and climatic conditions and prevention of pests and diseases requires an integrated approach. Integrated pest and disease management practices have been developed by research institutions but on balance, adoption by farmers is low ( Litsinger et al., 2009), either due to farmers’ inadequate knowledge on these practices or lack of skill to implement them. In this study, a little over a third of the respondents “did nothing” in the long run to manage pests and diseases. Our findings were consistent with similar studies by Torkpo et al. (2017) in Ghana and Gbaguidi et al. (2005) in Benin, who found that farmers hardly adopted the management strategies that prevented the spread of diseases. Farmers opined that they did not know what to do and others, even after reporting to the extension officers, received no help. It could be deduced that extension services and training support for pest and disease management are inadequate. It is worth mentioning that some farmers, based on their own experiences or advice from extension agents, employed some cultural practices such as killing the pests by hand, rouging, burning infested plants and weed management to improve crop vigor. This is consistent with Ntonifor et al. (2005) in Cameroon, who also found that nearly 30% of the farmers practiced rouging and other management practices. Nevertheless, only one person (1.1%) practiced crop rotation and fallowing. These are practices that have been promoted for a long while, but their application is still low, and this demonstrates farmers’ attitudes towards pest and disease management. So, as a long-term solution, some farmers resorted to pesticide application, which is expensive and could cause health hazards. Biological control was virtually nil (1.1%) as a single respondent sprayed boiled neem leaves, which was seen as effective. The neem tree ( Azadirachta indica), which is a common tree in the tropics including in Ghana, has been promoted by both agro-foresters and pathologists because of its multiple uses ( Saxena, 2015). Since this is common in the Ghanaian environment, it must be promoted among our smallholder farmers to sustainably manage pests and preserve the environment and biodiversity. We can conclude from the findings that integrated pest and disease management strategies are rarely implemented and farmers that implemented some practices were unaware of the benefits and thus may not do it diligently. Similar observations were made by Gbaguidi et al. (2005) in Benin and Torkpo et al. (2017) in Ghana. Based on these revelations, there is a need for strong partnership and all stakeholders must join in the fight against disease and pest attacks. Research institutions and the directorate of extension under MoFA still have much work to do in assisting farmers manage and control pests and diseases. Research should regularly build capacity of extension agents, develop packages of integrated pest and disease management strategies in simple, concise language and in local dialect that could easily be assimilated and used by farmers.

Studies have recommended integrated management measures such as cropping systems (intercropping with non-host plants), cultivation of improved resistant varieties, cultural practices (removal and destroying infested plants, crop rotation, fallowing, proper weed management), management of planting dates based on agro-ecology, and soil amendments, which usually results in high yields ( Afrane Okese, 2016; Alam et al., 2016; Dormon et al., 2007; Mathieu-Colas et al., 2009; and Fanou et al., 2017). Intercropping has been observed as a common practice among farmers ( Appiah-Kubi et al., 2015; Torkpo et al., 2017). Farmers applied this only as a diversification strategy to reduce production risk and were unaware of its disease management capacity. Cassava intercropping is done with short duration food crops like cereals and legumes, which offers a lot of advantages. Roots and tubers like yam and cocoyam are also intercropped with cassava ( Appiah-Kubi et al., 2015; Torkpo et al., 2017). With cassava being a heavy feeder ( Mathieu-Colas et al., 2009 and Biratu et al., 2019), intercropping with leguminous crops improves soil properties as crop residue serves as mulch. Cassava in association with yam demonstrates the symbiotic relationship between the two crops. The cassava serves as stakes for the yam, while farmers believe that the cassava bulks well in the yam mounds. Intercropping, on the other hand, could have negative effects on disease spread if done with alternative host plants of certain diseases ( Appiah-Kubi et al., 2015). For instance, yam could host fungus that causes cassava anthracnose ( Afrane Okese, 2016). Thus, it was not surprising that some farmers observed bud necrosis on their farms.

Planting improved pest and disease resistant varieties is another way of curtailing pests and diseases. With cassava mosaic disease being the most devastating in Africa ( Elegba et al., 2013), improved varieties are normally screened by breeders against this disease ( MyFarm Blog). All the improved varieties cultivated by the farmers are known to be resistant/tolerant to the cassava mosaic virus; however, only 25.5% of farmers cultivated only improved varieties (seven varieties identified out of the 26 released varieties). Though there is more room for improvement, this is higher than the 11% reported by Cudjoe et al. (2005). Most of the local varieties, though perceived to be high yielding with multiple uses, are susceptible to some of the cassava diseases and farmers should desist from their continuous cultivation. For instance, “Tuaka” can yield 32.3 tons per hectare but is susceptible to root rot and cassava mosaic virus ( Amenu, 2015).

The study observed that pests and diseases were not farmers’ top priority in choosing a new cultivar. Pest and disease resistance ranked fourth on farmers’ preferred traits. This demonstrates that though pests and diseases are discussed as a serious matter, farmers still do not consider it as such due to lack of knowledge on the extent of both physical and economic damage caused. Farmers need to be provided with empirical evidence of the effects of pests and diseases on their livelihoods to reorient their thinking. Despite the reforms, Ghana’s seed sector is passing new legislation, which seeks to increase availability of improved varieties that are not currently readily available for farmers to access. Failure in the seed supply system in Ghana has been attributed to governance challenges that affected all stages of the supply chain ( Adu-Gyamfi et al., 2018). Adu-Gyamfi et al. (2018) reported challenges such as limited involvement of smallholder farmers in setting breeding objectives, restricted private sector participation in seed production, under-resourced public regulatory bodies to ensure proper certification and over-reliance on weak public extension systems to disseminate improved varieties. Government policies should focus on the need to address these challenges for an effective seed system in the country.

When farmers were asked about the effectiveness of the pest and disease management strategies used, the responses showed that they were barely effective. It is evident that farmers crave more effective and efficient pest and disease management strategies. Farmers must be trained on integrated approaches to pest and disease management. This could be done by the research and extension directorate of MoFA. Information on this could also be disseminated to farmers in their local language through both print and electronic media in the form of fliers. Other channels that could be used to educate farmers, especially in the rural communities, are FM radio stations, social media (Whatsapp, Facebook, etc.) and televisions in addition to other regular sources of information.

In summary, the findings articulate the importance and prevalence of pests and diseases in the study regions, with high number of farmers affected. The study reveals good knowledge of pests but limited knowledge on diseases. The study has shown that mixed disease infections could occur, which are rarely reported in disease studies. However, integrated pest and disease management strategies were rarely applied due to a lack of knowledge and the seriousness farmers attached to pest and disease resistance traits of crops. Biological control was also rarely an option for pest and disease management. Supply of improved varieties and disease-free planting materials was still a challenge, which resulted in farmers depending on their local unimproved varieties. Although some farmers practiced intercropping, cultivated improved varieties and chose specific planting dates, they were unaware that these could have a direct correlation with pest and disease reduction on their farms.

Due to the movement of people and cross-border trade, there is the need for a multi-disciplinary collaboration within the sub-region to develop multiple resistant varieties and broad-spectrum pest and disease strategies to tackle the wide range of pests and diseases within the sub-region. The policy implication of our study is the need to improve farmers’ access to crops with improved desired traits and disease-free planting material through efficient dissemination pathways. Increased farmer knowledge on integrated cassava pest and disease management through public awareness creation and capacity building by extension agents and research institutions is also highly recommended. This measure will reduce pest and disease pressure on farms, leading to high productivity, enhanced food security, and increased incomes, among other benefits. From the research perspective, the study identified the need for the breeding team to make farmers an integral part of the breeding process, in terms of design and setting breeding priorities, to enhance uptake of improved varieties and appropriate management techniques. An empirical study using experimental tools is needed to validate yield losses reported by farmers.